For His Hope, Her Salvation, I knew I wanted the story set in Georgian England. But, Georgian England covers over a century. Many readers are familiar with Regency England, which spanned from 1811 to 1820, but the period is really a subset of Georgian England, which covered the reign of the House of Hanover from George I to George IV. (Readers can get a brief overview at Wikipedia of the House of Hanover, http://en.wikipedia.org/wiki/House_of_Hanover, and Regency England, http://en.wikipedia.org/wiki/Regency_England.)
During my search through Georgian England, I found a biography on William Pitt the Younger at http://en.wikipedia.org/wiki/William_Pitt_the_Younger. It inspired a thought about what if the rogue had come back to save the Marquess of Rockingham (http://en.wikipedia.org/wiki/Charles_Watson-Wentworth,_2nd_Marquess_of_Rockingham) and thereby prevent Pitt from becoming Prime Minister again. While I eventually discarded this plot in favor of something else, it did give me a time period to work with…the early 1780s.
Next, I searched for articles on fashion. Doing a Google search yielded http://www.oldandsold.com/articles09/clothes-28.shtml, a website describing fashion of the eighteenth century, http://www.electricscotland.com/history/highland_dress.htm, which is an interesting write up on the Act against the Highland Dress and has absolutely nothing to do with my story, and the reliable Wikipedia link to fashion from 1750-1795, http://en.wikipedia.org/wiki/1750%E2%80%931795_in_fashion, which is where I ended my search.
Please note, I don't rely strictly on Wikipedia as the information is not always reliable. I also cross check the information with history books from my personal library. Books such as The Lives of the Kings & Queens of England by Antonia Fraser, a brief synopsis of the reign of each of the kings and queens of England from William the Conqueror to Elizabeth II. I find her writing to be interesting and informative. She likes to throw in juicy tidbits every now and again. Royal Paramours by Dulcie M. Ashdown. I picked this book up for a couple of dollars and found it vastly amusing since I have an avid interest in torrid historical royal affairs. Who can resist a book with a chapter titled “The Maypole and the Elephant”? Georgiana by Amanda Foreman. A beautifully written book about the Duchess of Devonshire, whose life was flamboyant, but sad, at least to me. It covers the period from her birth in 1757 to her death in 1806.